Borrelia burgdorferi, the agent of Lyme disease, causes arthritis partly through molecular mimicry. The outer surface protein that cross-reacts with LFA-1 on joint synoviocytes, contributing to autoimmune arthritis, is:

• A OspA (outer surface protein A) ✓
• B OspC (outer surface protein C)
• C VlsE (variable major protein-like sequence E)
• D BBK32 fibronectin-binding protein

Explanation

OspA of B. burgdorferi shares a T-cell epitope with LFA-1 (lymphocyte function-associated antigen 1) on human joint synovia cells; in genetically susceptible individuals (HLA-DRB1*0401 alleles), anti-OspA T cells cross-react with LFA-1 on synoviocytes, perpetuating inflammation even after antibiotic eradication of spirochetes (antibiotic-refractory Lyme arthritis). OspC is expressed early in infection mediating tick-human transmission and evades complement. VlsE undergoes antigenic variation during persistent infection to evade antibody responses. BBK32 mediates fibronectin binding and dissemination.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.